Over on GitHub, Martin (mgrone) recently released stream1090, a new open source C++ Mode-S demodulator that takes a fundamentally different approach to finding aircraft messages. Rather than searching for the traditional preamble pulse sequence as dump1090 and readsb do, stream1090 continuously maintains shift registers and identifies valid messages based on their CRC checksum. In busy airspace where preambles can be corrupted by overlapping signals, this approach theoretically cannot miss a message as long as the data itself is intact. Since the CRC is always being computed, it can also be used for single-bit error correction.

The software supports both RTL-SDR and Airspy dongles. It's lightweight enough to run on a Raspberry Pi Zero 2W. Stream1090 is a demodulator only, designed to pipe output into readsb or dump1090-fa via socat, slotting into your existing ADS-B stack as a drop-in replacement for the demodulation stage.

If you have an ADS-B station in a high-traffic area, let us know if Stream1090 increases your message rate! There is also a discussion about it on FlightAware, where many people have indicated that they are getting great results.